Electrical Steel Usage and Topology Design Method for HTS Wind Generators

High-temperature superconducting (HTS) magnet can provide a significantly high magnetomotive force (MMF) for generators. However, elevated MMF levels can lead to saturation of the ferromagnetic materials. In the case of involving high MMF, the removal of ferromagnetic materials may increase the power density, yet it still results in a reduction of magnetic flux. For generator with iron yoke and teeth, theoretical derivations and simulation analyses of HTS generators with varying geometric parameters reveal two key design directions, i.e., optimal slot width and saturated yoke thickness. And a design scheme of 22 MW superconducting wind generator is provided. In the case of generators with partial iron, the no-load characteristic curve is employed to assess the additional MMF required following the removal of electrical steel materials. Furthermore, the second derivative of no-load characteristic is proposed as the criterion for the trade-off between electrical steel material and MMF. This paper presents a comprehensive design of a superconducting generator and a comparative analysis of iron topologies, provide essential guidance for designing different iron topology design of HTS generator.